Over the years, the layering
principle, which segments network functions and specifies standard interfaces
between layers, has served the networking community quite well. The
standardization of functional interactions between the layers has allowed
developers to work independently of each other. However, some recent trends
have created the need to better understand the interaction between layers.
These trends include the need to integrate various wireless applications over
the Internet, the need to reduce the redundancy between layers and thus reduce
the size and weight of wireless terminals, and the growing importance of QoS
and energy conservation at various layers. Specifically, it is important to understand the effect of
lower layer control on end-to-end reliability and performance, the effect of
upper layer protocols and management on link operations, and the effect of
lower layer mechanisms on TCP, which dominates Internet applications. Our
objective is to create infrastructure and algorithms to enable more optimal
performance of the wireless system, by adopting an integrated, multi-layer
approach. The design and optimization process will combine innovations at
physical layers, control and scheduling at MAC layer, efficient routing and
admission control at network layer, dynamics and flow control at transport
layer, and specific requirements at application layers.